Creating Backup Sets   «Prev  Next»

Lesson 1

Creating and Managing Backup Sets

Earlier in this course, you learned about image copies. Image copies have advantages and disadvantages. On the plus side, you can use an image copy as a back up without having to do a restore. On the other hand, it is difficult to make an image copy that is both consistent and up to date, and also difficult and less flexible to use parallel processes to do an image copy backup.
In this module, you will explore backup sets, the other backup format. By the end of this module, you'll be able to:
  1. Review the concept of a backup set
  2. Identify the syntax of the backup command
  3. Discuss how and why Recovery Manager (RMAN) multiplexes backup sets
  4. Demonstrate how Recovery Manager parallelizes backup sets
  5. Identify data file backup sets
  6. Identify archive log backup sets

In today's IT environment, backup sets are the most commonly used backup format, so the knowledge gained in this module will benefit you in the workplace.

Configuring Default Type for Backups:

The BACKUP command can create either backup sets or image copies. For disk, you can configure RMAN to create either backup sets or image copies as its default backup type with the CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO command. The default backup type for disk is an uncompressed backup set.

Note: Because RMAN can write an image copy only to disk, the backup type for tape can only be a backup set.
RMAN can create backup sets using binary compression. You can configure RMAN to use compressed backup sets by default on a device type by specifying the COMPRESSED option in the 
BACKUP TYPE TO ... BACKUPSET

clause. To disable compression, use the CONFIGURE DEVICE TYPE command with arguments specifying your other desired settings, but omit the COMPRESSED keyword.
To configure the default type of backup:
  1. Start RMAN and connect to a target database and a recovery catalog (if used).
  2. Configure backup sets or image copies as the default backup type.
The following examples configure the backup type for disk backups to copies and backup sets: 
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COPY; # image copies
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO BACKUPSET; # uncompressed

The following examples configure compression for backup sets: 
CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET;
CONFIGURE DEVICE TYPE sbt BACKUP TYPE TO COMPRESSED BACKUPSET;

In the next lesson, you will review what a backup set is.